In the art of electrical heating elements for rear view mirrors used on motor vehicles, for example, as disclosed in U.S. Pat. Nos. 3,052,787, 4,237,366, 4,410,790 and 4,631,391, it is known to use self-regulating electrical resistance heater disks of a ceramic positive temperature coefficient of resistivity (PTC) which are connected to the low voltage DC power supply of the motor vehicle. The PTC heaters are usually formed in the shape of a disk or platelets which are placed in contact between electrically conductive plates, and one of the plates is attached to the back surface of the mirror as shown in above mentioned U.S. Pat. No. 4,631,391. The heat generated by the PTC discs or platelets is conducted by the metal plate over the back surface of the mirror to melt ice and/or snow in contact with the mirror and to defrost the mirror. The metal plate in contact with the mirror conducts the heat generally uniformly across the entire back surface of the mirror even though the mirror surface temperature is not uniform due to the ice or snow. In addition, the cost of producing mirrors with heater assemblies such as shown in the above patents is relatively high, primarily in view of the labor involved in the manufacturing of the mirror and heater assemblies.